I bought a beautiful telescope goldie from here they have very nice fish on here. Some can be pretty expensive but you won't see goldfish this size and quality anywhere else, at least that I know of. He only ships fed ex overnight which I think is really important with fish this size especially goldfish because of the amount of waste they produce. I'm sure he does fast them first but I think it shows that he cares his fish make it through their travel. He also ships them in bags with four corners on the bottom instead of two so they don't get caught up. My fish was packed very well she arrived full of energy thrashing around. He also gives you two weeks to hold your fish there so if you want to add any from the next auction you can ship them together to save on cost. The auctions are usually every Friday at 8:00 PM and end Sunday at 8:00 PM.
This is my beautiful girl Big Black.
I've been a goldfish keeper of 8 years and I agree with the site mentioned above. Another loved source is goldfish sales and goldfish information from Rain Garden
I have never bought from either source, but I've heard many wonderful stories and seen many beautiful photos of fish from those two sources.
I suggest joining Kokos Goldfish Forum to learn of even more sources and trusted sellers.